Prior to medical and surgical procedures or treatments, sterilization of medical devices and instruments prior to their use is necessary to reduce the risk of infection from microbes on such equipment. Various sterilization techniques are utilized in the medical field, such as irradiation of equipment, treatment using antimicrobial solutions, and temperature sterilization techniques. One of the most commonly employed techniques is sterilization using an autoclave, which involves placement of the equipment to be sterilized within a chamber which is subsequently heated to a temperature and for a time period sufficient to kill microbial agents which can be present on the equipment.
Sterilization containers are sometimes used to house surgical instruments and other devices to be sterilized. Typical sterilization containers are constructed of a lid and base portion, and a vent portion located on the lid, base or both. The vent portion permits the movement of gases to accommodate the changes in pressure created by increasing or decreasing temperatures of the internal and external environments of the container. In order to prevent contamination by the handling and storage of sterilization containers, filters can be positioned in relation to the vent portion to permit the transport of gases but reduce or prevent the transport of microbes.
Filter systems for sterilization containers have been developed. Typical filter systems include a filter retainer and an associated locking mechanism to secure the filter in place relative to the vent portion of the container. Such a filter retention system is described in Nalepa et al. U.S. Pat. No. 5,968,459, which describes a filter retention system including a rotating locking plate which secures a filter retaining plate and filter to a sterilization container having vent openings. One drawback of this system, however, is that it requires a turning or pivoting movement by the user's hand, and does not provide a penetration resistant structure to protect the filter from piercing. Another filter system is described in Spence U.S. Pat. No. 4,783,321, which discloses a penetration resistant filter retaining system having an upper retainer disc and lower retainer disc. This system, however, requires precise positioning of the retainer discs in relation to one another and the vent openings, and does not contain a single, centrally located locking mechanism.
There is a need for improved filter systems useful for sterilization containers that facilitate the filter retention function of the container while maintaining the properties required for sterilization processes. There is a further need for filter systems which secure a filter onto a sterilization container, protect the filter from damage or unintended movement, and reduce the likelihood of contamination both during and following sterilization. There is yet a further need for filter systems which are ergonomic and afford the user a comfortable assembly and preparation, especially when such activities are repeated tasks.